In this interview, David Zierler, Oral Historian for AIP, interviews Daniel Z. Freedman, Professor Emeritus of Applied Mathematics and Physics at MIT and long-term visiting professor at Stanford. Freedman explains his understanding of the term’s mathematical physics and physical mathematics, and he bemoans the broad decoupling of experiment and theory in physics. He recounts his upbringing in West Hartford, Connecticut, and he describes his undergraduate education at Wesleyan. Freedman describes his early attachment to theory and his graduate work at the University of Wisconsin, where he worked under the direction of Ray Sawyer on Regge poles. He discusses his postdoctoral research as a NATO fellow in Europe at CERN and Imperial College London, and he conveys the sense of excitement at the time about the weak and strong interactions. Freedman describes his appointment at UC Berkeley before joining the Institute for Advanced Study, and he explains the opportunity that led to his faculty job at Stony Brook. He reflects on his interactions with Yang and he narrates the origins of supersymmetry, and shortly after, the origins of supergravity. Freedman explains what is “super” in supergravity, supersymmetry, and super-space, and he describes why the reality of supersymmetry must be true even if we lack the tools to see it. He explains his decision to move to MIT, and he connects the arc from the 1984 string revolution to the discovery of AdS/CFT in 1997. Freedman describes winning the Dirac medal and subsequently the Breakthrough Prize, which he understood as confirmation in the community about the importance of supergravity. At the end of the interview, Freedman connects his work to larger questions in cosmology and astrophysics, he expresses surprise by the increasing centrality of mathematics to physics, he explains his early work on neutrino scattering and why after 40 years, his original intuition has been vindicated.